Illustration of HapMap and NIEHS SNP. Figure 2A represents the genes in first condition (set A), i.e. not all the SNPs in HapMap are identified in NIEHS dataset and vice versa. The shaded area is the overlapping SNPs between the two datasets. Figure 2B represents the genes in second condition (set B) where the SNPs in HapMap are all genotyped in the NIEHS dataset or the subset of SNPs in HapMap can cover all other SNPs in HapMap.